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watchdog: at91sam9_wdt: Convert to use the watchdog framework
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According to Documentation/watchdog/convert_drivers_to_kernel_api.txt,
remove the file_operations struct, miscdevice, and obsolete includes

Since the at91sam watchdog inherent characteristics, add the watchdog
operations: at91wdt_start, at91wdt_stop and at91wdt_ping.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Cc: linux-watchdog@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
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Wenyou Yang authored and Wim Van Sebroeck committed Mar 1, 2013
1 parent 2dd7b24 commit 490ac7a
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Showing 2 changed files with 43 additions and 119 deletions.
1 change: 1 addition & 0 deletions drivers/watchdog/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -125,6 +125,7 @@ config AT91RM9200_WATCHDOG
config AT91SAM9X_WATCHDOG
tristate "AT91SAM9X / AT91CAP9 watchdog"
depends on ARCH_AT91 && !ARCH_AT91RM9200
select WATCHDOG_CORE
help
Watchdog timer embedded into AT91SAM9X and AT91CAP9 chips. This will
reboot your system when the timeout is reached.
Expand Down
161 changes: 42 additions & 119 deletions drivers/watchdog/at91sam9_wdt.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -18,11 +18,9 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
Expand Down Expand Up @@ -68,19 +66,17 @@ module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

static struct watchdog_device at91_wdt_dev;
static void at91_ping(unsigned long data);

static struct {
void __iomem *base;
unsigned long next_heartbeat; /* the next_heartbeat for the timer */
unsigned long open;
char expect_close;
struct timer_list timer; /* The timer that pings the watchdog */
} at91wdt_private;

/* ......................................................................... */


/*
* Reload the watchdog timer. (ie, pat the watchdog)
*/
Expand All @@ -95,39 +91,37 @@ static inline void at91_wdt_reset(void)
static void at91_ping(unsigned long data)
{
if (time_before(jiffies, at91wdt_private.next_heartbeat) ||
(!nowayout && !at91wdt_private.open)) {
(!watchdog_active(&at91_wdt_dev))) {
at91_wdt_reset();
mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);
} else
pr_crit("I will reset your machine !\n");
}

/*
* Watchdog device is opened, and watchdog starts running.
*/
static int at91_wdt_open(struct inode *inode, struct file *file)
static int at91_wdt_ping(struct watchdog_device *wdd)
{
if (test_and_set_bit(0, &at91wdt_private.open))
return -EBUSY;
/* calculate when the next userspace timeout will be */
at91wdt_private.next_heartbeat = jiffies + wdd->timeout * HZ;
return 0;
}

at91wdt_private.next_heartbeat = jiffies + heartbeat * HZ;
static int at91_wdt_start(struct watchdog_device *wdd)
{
/* calculate the next userspace timeout and modify the timer */
at91_wdt_ping(wdd);
mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);

return nonseekable_open(inode, file);
return 0;
}

/*
* Close the watchdog device.
*/
static int at91_wdt_close(struct inode *inode, struct file *file)
static int at91_wdt_stop(struct watchdog_device *wdd)
{
clear_bit(0, &at91wdt_private.open);

/* stop internal ping */
if (!at91wdt_private.expect_close)
del_timer(&at91wdt_private.timer);
/* The watchdog timer hardware can not be stopped... */
return 0;
}

at91wdt_private.expect_close = 0;
static int at91_wdt_set_timeout(struct watchdog_device *wdd, unsigned int new_timeout)
{
wdd->timeout = new_timeout;
return 0;
}

Expand Down Expand Up @@ -163,107 +157,34 @@ static int at91_wdt_settimeout(unsigned int timeout)
return 0;
}

/* ......................................................................... */

static const struct watchdog_info at91_wdt_info = {
.identity = DRV_NAME,
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};

/*
* Handle commands from user-space.
*/
static long at91_wdt_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_value;

switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &at91_wdt_info,
sizeof(at91_wdt_info)) ? -EFAULT : 0;

case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);

case WDIOC_KEEPALIVE:
at91wdt_private.next_heartbeat = jiffies + heartbeat * HZ;
return 0;

case WDIOC_SETTIMEOUT:
if (get_user(new_value, p))
return -EFAULT;

heartbeat = new_value;
at91wdt_private.next_heartbeat = jiffies + heartbeat * HZ;

return put_user(new_value, p); /* return current value */

case WDIOC_GETTIMEOUT:
return put_user(heartbeat, p);
}
return -ENOTTY;
}

/*
* Pat the watchdog whenever device is written to.
*/
static ssize_t at91_wdt_write(struct file *file, const char *data, size_t len,
loff_t *ppos)
{
if (!len)
return 0;

/* Scan for magic character */
if (!nowayout) {
size_t i;

at91wdt_private.expect_close = 0;

for (i = 0; i < len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V') {
at91wdt_private.expect_close = 42;
break;
}
}
}

at91wdt_private.next_heartbeat = jiffies + heartbeat * HZ;

return len;
}

/* ......................................................................... */

static const struct file_operations at91wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.unlocked_ioctl = at91_wdt_ioctl,
.open = at91_wdt_open,
.release = at91_wdt_close,
.write = at91_wdt_write,
static const struct watchdog_ops at91_wdt_ops = {
.owner = THIS_MODULE,
.start = at91_wdt_start,
.stop = at91_wdt_stop,
.ping = at91_wdt_ping,
.set_timeout = at91_wdt_set_timeout,
};

static struct miscdevice at91wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &at91wdt_fops,
static struct watchdog_device at91_wdt_dev = {
.info = &at91_wdt_info,
.ops = &at91_wdt_ops,
.min_timeout = 1,
.max_timeout = 0xFFFF,
};

static int __init at91wdt_probe(struct platform_device *pdev)
{
struct resource *r;
int res;

if (at91wdt_miscdev.parent)
return -EBUSY;
at91wdt_miscdev.parent = &pdev->dev;

r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r)
return -ENODEV;
Expand All @@ -273,16 +194,20 @@ static int __init at91wdt_probe(struct platform_device *pdev)
return -ENOMEM;
}

at91_wdt_dev.timeout = heartbeat;
at91_wdt_dev.parent = &pdev->dev;
watchdog_set_nowayout(&at91_wdt_dev, nowayout);

/* Set watchdog */
res = at91_wdt_settimeout(ms_to_ticks(WDT_HW_TIMEOUT * 1000));
if (res)
return res;

res = misc_register(&at91wdt_miscdev);
res = watchdog_register_device(&at91_wdt_dev);
if (res)
return res;

at91wdt_private.next_heartbeat = jiffies + heartbeat * HZ;
at91wdt_private.next_heartbeat = jiffies + at91_wdt_dev.timeout * HZ;
setup_timer(&at91wdt_private.timer, at91_ping, 0);
mod_timer(&at91wdt_private.timer, jiffies + WDT_TIMEOUT);

Expand All @@ -294,13 +219,12 @@ static int __init at91wdt_probe(struct platform_device *pdev)

static int __exit at91wdt_remove(struct platform_device *pdev)
{
int res;
watchdog_unregister_device(&at91_wdt_dev);

res = misc_deregister(&at91wdt_miscdev);
if (!res)
at91wdt_miscdev.parent = NULL;
pr_warn("I quit now, hardware will probably reboot!\n");
del_timer(&at91wdt_private.timer);

return res;
return 0;
}

#if defined(CONFIG_OF)
Expand All @@ -326,4 +250,3 @@ module_platform_driver_probe(at91wdt_driver, at91wdt_probe);
MODULE_AUTHOR("Renaud CERRATO <r.cerrato@til-technologies.fr>");
MODULE_DESCRIPTION("Watchdog driver for Atmel AT91SAM9x processors");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

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